Question

Explain the development of the male gemetophyte in plants.

Answer 1

The male gametophyte develops from a microspore produced in the anther.

1. A diploid pollen mother cell undergoes meiosis to form a tetrad of four haploid microspores. The microspores separate and each develops into a pollen grain.
2. The pollen grain forms a protective wall: the outer exine, containing sporopollenin, and the inner intine. Thin regions in the exine form germ pores.
3. The microspore nucleus divides mitotically into a large vegetative cell and a smaller generative cell. In most angiosperms pollen is shed at this two-celled stage.
4. After compatible pollen lands on a receptive stigma, the intine grows through a germ pore to form a pollen tube. The generative cell divides mitotically to form two male gametes; in some plants this division occurs before pollen is shed.

Thus, the pollen grain and its developing pollen tube constitute the male gametophyte.